/*
day346 
2020.8.8 
*/
#include<iostream>
#include<cstdlib>
#include<vector>
using namespace std;


class Solution {
public:
    vector<vector<int>> subsets(vector<int>& nums) {
		vector<vector<int>> res;
		res.push_back({});
		int size=res.size(); 
		for(auto n : nums)
		{
			for(int i=0;i<size;++i)
			{
				res.push_back(res[i]);
				res.back().push_back(n);
			}	
			size=res.size();
		}
		
		return res;
    }
};

int main()
{
	return 0;
}
